From: tomas_matousek at hotmail dot com
Operating system: WinXP
PHP version: 5.0.1
PHP Bug Type: Arrays related
Bug description: Nondeterministic behavior of array inner pointer
Description:
------------
In the manual page describing each() function is the following caution:
"Because assigning an array to another variable resets the original arrays
pointer, ..."
I think that this is a bug, although it is documented and treated as
feature.
I realized that the pointer is reset when a copy of an array is made.
However, PHP makes some optimizations which prevents unnecessary array
copying (which is good feature).
Since these optimizations are not known for users (and shouldn't be) the
behavior of inner pointer is thus non-deterministic from user's point of
view.
See the follwoing code.
Its output depends on whether the statement $b[] = 1; is commented or
not.
Reproduce code:
---------------
function f($a) { $b = $a; /*$b[] = 1;*/ return $b; }
$arrayOuter = array("key1","key2");
$arrayInner = array("0","1");
while(list(,$o) = each($arrayOuter))
{
$q = f($arrayInner);
while(list(,$i) = each($arrayInner))
{
print "inloop $i for $o\n";
}
}
Expected result:
----------------
inloop 0 for key1
inloop 1 for key1
Actual result:
--------------
inloop 0 for key1
inloop 1 for key1
inloop 0 for key2
inloop 1 for key2
--
Edit bug report at http://bugs.php.net/?id=29950&edit=1
--
Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=29950&r=trysnapshot4
Try a CVS snapshot (php5.0): http://bugs.php.net/fix.php?id=29950&r=trysnapshot50
Try a CVS snapshot (php5.1): http://bugs.php.net/fix.php?id=29950&r=trysnapshot51
Fixed in CVS: http://bugs.php.net/fix.php?id=29950&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=29950&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=29950&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=29950&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=29950&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=29950&r=support
Expected behavior: http://bugs.php.net/fix.php?id=29950&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=29950&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=29950&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=29950&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=29950&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=29950&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=29950&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=29950&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=29950&r=float
